During WWII a young women named Mrs de Florian locked her Parisian apartment and moved to the South of France. She never returned to it, but she payed her rent faithfully until she died 70 years later. As the Telegraph reports in the article about the opening of the apartment:

Behind the door, under a thick layer of dusk lay a treasure trove of turn-of-the-century objects including a painting by the 19th century Italian artist Giovanni Boldini.The woman who owned the flat had left for the south of France before the Second World War and never returned.

But when she died recently aged 91, experts were tasked with drawing up an inventory of her possessions and homed in on the flat near the Trinité church in Paris between the Pigalle red light district and Opera.

Entering the untouched, cobweb-filled flat in Paris' 9th arrondissement, one expert said it was like stumbling into the castle of Sleeping Beauty, where time had stood still since 1900.

"There was a smell of old dust," said Olivier Choppin-Janvry, who made the discovery. Walking under high wooden ceilings, past an old wood stove and stone sink in the kitchen, he spotted a stuffed ostrich and a Mickey Mouse toy dating from before the war, as well as an exquisite dressing table.

But he said his heart missed a beat when he caught sight of a stunning tableau of a woman in a pink muslin evening dress.

The painting was by Boldini and the subject a beautiful Frenchwoman who turned out to be the artist's former muse and whose granddaughter it was who had left the flat uninhabited for more than half a century.

As interesting as the story about the painting is, the greater mystery is why de Florian preserved those rooms for so long without ever returning. Were they a bittersweet memory she couldn't release or just a return trip she always intended but never made?